Circulatory system (transport in animals) Flashcards
What types of organisms have what SA:V types?
Small or single celled organisms have a larger SA:V
Large or multi celluled organisms have a lower SA:V
Why do single celled organisms and very few small multi celled not need specialised transport systems?
Diffusion through the cell surface membrane provides sufficient oxygen and nutrients while also ridding themselves of waste products like carbon dioxide
Why do large multi celled organisms need specialised transport systems?
Oxygen and other nutrients are used up by the first 2 layers of cells which means other cells do not get the required oxygen. Diffusion also takes too long and the distance is to great for cells that are far away from the surface
Why do mammals require more energy than reptiles?
Mammals are warm blooded so they do more respiration to maintain their body temperature.
Reptiles are cold blooded so they do less respiration as their body temperature regulates much easier
What is the difference between open and closed circulatory systems?
Open circulatory systems contain either no or very few blood vessels and is common in invertebrates and other insects
Closed circulatory systems use blood vessels to transport blood and oxygen throughout the body and is common in vertebrates and other large organisms
What is the primary difference between a single and double circulatory system?
Single circulatory systems involves blood only passing through the heart once for a complete circulation
Double circulatory systems involves blood passing through the heart twice for a complete circulation
Explain the pathway of blood through a fish (single circulatory)
Deoxygenated blood from the ventricle in the heart passes to the capillaries in the gills through an artery to become oxygenated,
It then flows to the capillaries in the organs where the oxygen diffuses out making it deoxygenated blood again,
It then flows back to the heart into the atrium through a vein
Explain the pathway of blood through a mammal (double circulatory)
Deoxygenated blood from the right ventricle flows to the lungs through the pulmonary artery to become oxygenated,
The blood becomes oxygenated as oxygen diffuses into it through the capillaries in the lungs,
It then flows to the left atrium through the pulmonary vein where it is then forced into the left ventricle,
The blood from the left ventricle then flows to the capillaries throughout the body through the aorta where oxygen diffuses out into muscles and organs,
Once becoming deoxygenated blood again it flows back to the heart through the vena cava into the right atrium
Explain the flow of blood through a partial double circulatory system and the types of animals where it is present
It is present in amphibians such as frogs and some reptiles
Deoxygenated blood from the right atrium flows into the single ventricle and becomes partially oxygenated,
It then flows to the capillaries in the lungs to become fully oxygenated and then into the left atrium,
From the left atrium it flows back into the single ventricle and becomes partially oxygenated again,
The single ventricle only has one artery which branches to the lungs and the rest of the body,
The partially oxygenated blood that flows to the body diffuses its oxygen into organs and muscles in the capillaries which leaves deoxygenated blood to flow back to the right atrium
Explain the terms pulmonary and systemic circulatory systems
Pulmonary refers to blood flow to and from the lungs
Systemic refers to blood flow throughout the rest of the body
What are the names of the blood vessels attached to the Heart, their function and side of the Heart?
Superior and inferior vena cava transport deoxygenated blood to the right atrium (right side),
Pulmonary artery transports deoxygenated blood to the lungs from the right ventricle (right side),
Pulmonary vein transports oxygenated blood from the lungs to the left atrium (left side),
Aorta transports oxygenated blood from the left ventricle to capillaries throughout the body (left side)
What are the names and roles of the chambers of the Heart?
Right atrium receives deoxygenated blood from the body and forces it into the right ventricle,
Right ventricle receives deoxygenated blood from the right atrium and sends the blood to the lungs,
Left atrium receives oxygenated blood from the lungs and forces it into the left ventricle,
Left ventricle receives oxygenated blood from the left atrium and sends it to the rest of the body
What are the three types of valves in the heart and where are they located?
Tricuspid/right atrioventricular valve is located between the right atrium and right ventricle
Bicuspid/left atrioventricular valve is located between the left atrium and left ventricle
Semilunar valves are located between the right ventricle and pulmonary artery and the left ventricle and the aorta
What is the role of veins?
To prevent backflow
What prevents the valves from turning inside out?
Tendinous chords attached to the sides of the chambers of the hear or blood vessels
What tissue is the heart mainly made of and how is it specialised to its role?
Mainly made of cardiac muscle
Contains a high concentration of mitochondria,
Contains a high concentration of myoglobin,
Only respires aerobically,
Cells of the tissue are connected by intercalated discs
What is the average thickness of the Hearts chambers in a mammal and why?
Atria-2mm
Left ventricle-9mm
Right ventricle-16mm
The atria don’t need to be as thick to build pressure due to the blood they transport only going a small distance and being assisted by gravity,
Left ventricle transports blood throughout the body so lots of pressure is needed to transport blood and needs to overcome the systemic circulation resistance,
Right ventricle needs to transport blood a medium distance and doesn’t need to overcome much pressure so the walls are thicker but not very thick
What is the average BPM and time for one full contraction?
Average BPM is 60-80
The heart fully contracts every 0.7-0.8 seconds
What are the 3 phases of the Heart beat?
Diastole- Filling or relaxed phase
Atrial systole- Atrial walls contract
Ventricular systole- Ventricle walls contract
What happens during diastole?
Walls of the Heart relax,
Blood flows into the Heart from the body,
The pressure partly opens the AV valves,
Blood moves from the atria to the ventricles,
SL valves are closed
What happens during atrial systole?
Left and right atrium walls contract,
Pressure in the atria increases,
All blood is forced into the ventricles,
AV valves are fully open,
SL valves are closed
What happens during ventricular systole?
Once ventricles are full the walls contract starting at the apex,
Causes the AV valves to close,
All valves temporarily close,
Blood is forced from the ventricles into the arteries,
SL valves open
What is the state of the atrioventricular valves during the different phases of the cardiac cycle?
Diastole- Partly open
Atrial systole- Fully open
Ventricular systole- Closed
What is the state of the semilunar valves during the different phases of the cardiac cycle?
Diastole- Closed
Atrial systole- Closed
Ventricular systole- Fully open
What is the full cardiac conduct cycle?
1) Sinoatrial node(pacemaker) generates an electrical impulse known as the wave of excitation,
2)The impulse travels over the atria walls causing them to contract and is stopped by a band of non conducting tissue to prevent the spread to the ventricles,
3)The impulse if picked up by the atrio-ventricular node which delays the impulse by 0.1 seconds to allow the atria to empty,
4) The impulse travels down the septum via the Bundles of His to the apex of the Heart which causes the ventricles to contract
